When drywall panels are installed in a building, and the seams taped, prior to painting the wall surface, there is often applied a spray texture, which is followed by painting. The spray texture will provide a desirable background pattern, and also obscure some of the seams that might appear in the drywall surface.
There are in the prior art various spray texturing tools or devices which utilize pressurized air to spray the texture material onto the wall surface. Some of these use compressed air as the gaseous medium to spray the textured material, with the pressurized air being derived from a remote source that feeds the air through a hose to the tool. There are also tools which are totally handheld, with the pressurized air being produced by manually reciprocating the piston of an air pump that is built into the tool.
When an existing drywall surface is being repaired, quite often a small section of drywall will be removed and another piece of drywall put in its place. The seams of this piece of drywall must then be taped, and (if the surrounding surface is textured) then have a texture surface treatment that would make it match with the surrounding drywall surface. It is, of course, desirable to have the spray pattern on the patch match that of the surrounding surface.
Also, when a rather small "patch" of drywall is to be spray textured, there is the matter of convenience. One approach has been simply to provide the spray texture material in an aerosol can, and the textured material is dispensed directly from the can to be sprayed onto the drywall surface. However, one of the considerations is how this can be accomplished in a manner to provide proper matching of the texture with that which is on the surrounding drywall.
U.S. Pat. No. 5,037,011 (Woods) discloses such an aerosol texture spraying device where the spray texture material is dispensed directly from the nozzle of the aerosol can. In a commercial embodiment of a device such as this, when there is higher pressure in the container, there is a relatively fine spray pattern. For a more coarse pattern (i.e. with larger particle sizes), the can is inverted and the nozzle depressed to dispense a certain amount of the propellant gas for a few seconds. Then the can is turned upright and the spray texture material dispensed at a lower pressure to provide the spray pattern with larger particle sizes.
U.S. Pat. No. 5,310,095 issued to the present Applicant discloses an apparatus for discharging a spray texture material through a nozzle means having a nozzle discharge opening to dispense this material. There is further provided a first delivery tube means having a first discharge passageway of a first predetermined cross-sectional area. The material discharge apparatus is operated to cause the textured material to be discharged through the tube means. Then a second discharge tube means is positioned to receive material from the discharge nozzle means, and this second tube means has a second discharge passageway with a second predetermined cross-sectional area different from the first cross-sectional area. Thus, the No. '095 patent disclosed obtaining a finer spray pattern by utilizing a tube means with a passageway having a lesser cross-sectional area and a coarse pattern by discharging said material through the tube means having a greater cross-sectional area.
A primary problem with the method disclosed in the No. '095 patent is that a plurality of parts must be manufactured, shipped, sold, assembled and stored by the end user in order to maintain the capability of the product to create different texture patterns.
With the No. '095 patent, three straws must be sold in connection with the aerosol can. While this method is quite inexpensive from a manufacturing point of view, the shipping and sale of the product are somewhat complicated by the need to attach the three straws to the aerosol can. Further, the end user must install the straws into the actuating member of the aerosol can; this is difficult to accomplish without depressing the actuating member and discharging some of the texture material. Also, after the product disclosed in the No. '095 patent is used, the user must store the straws such that they are easily available when needed.
Accordingly, the need exists for a spray texturing device that is easy to use, inexpensive to manufacture, does not require user assembly, and does not require the shipment and storage of a plurality of parts.